Pseudo spin valve MRAM cells with sub-micrometer critical dimension

Pseudo spin valve cells with critical dimension 0.15 μm were fabricated using e-beam lithography and exercised with an externally applied magnetic field. Data indicate that bit end shaping is important for cell stability. At such small critical dimensions, the field required to write a cell is large, approximately 180 Oe for cells with 60 Å and 80 Å thick magnetic layers. A single-domain model was used to predict switching thresholds for various word field rise times. Results indicate that significant lowering of the write field thresholds may occur for rise times less than about 2 ns